This application is a continuation-in-part of Mohl et al., U.S. patent application Ser. No. 583,753, filed Feb. 27, 1984, now abandoned.
This invention relates to intermittent periodic occlusion of the coronary sinus in order to accomplish retroperfusion, i.e., repeatedly temporarily blocking the major vein which collects blood from the heart muscle in order to cause venous blood to flow back from the normal contracting myocardium to reach ischemic portions of the heart muscle.
Arterial blood which feeds the heart muscle is able to pass through and nourish healthy heart tissue, but has difficulty in reaching the ischemic tissue. This reduces the delivery of nutrients to, and the carrying away of the waste products of metabolism (metabolites) from, the ischemic tissue.
It has been proposed to reach the ischemic tissue by causing blood to flow in a reverse direction from the coronary sinus back through the coronary veinous system. Such retroperfusion has been attempted by feeding blood into the coronary sinus from another source, either by permanently connecting an artery to the coronary sinus or by temporarily inserting into the sinus a catheter supplied with blood which has been taken from a remote artery and passed through a blood pump outside the patient's body.
Another proposed technique for retroperfusion uses an inflatable balloon held on the end of a catheter to intermittently occlude the coronary sinus. Blood pressure in the sinus then rises as the heart beats so that blood received in the sinus through the healthy tissue of the heart muscle is forced back into the ischemic tissue. In such intermittent coronary sinus occlusion the balloon end of the catheter is inserted percutaneously or intraoperatively. The other end of the catheter is supPlied with gas or liquid by a pump which can be controlled to cause the balloon to inflate and deflate cyclically, for example at a rate synchronized with the heart pulse rate, or on the basis of pressure.